Heat sink compound

[Shannen Durphey]

diy_efi at efi332.eng.ohio-state.edu wrote:
> 
> The positive diode pack is stacked on top of the negative diode
> pack and the whole thing is screwed down to the case with three
> screws, all of which have plastic insulators on them, obviously
> needed since the screws pass through both diode sets.  The neg
> side is to conduct to the case just by clamping pressure to the
> case but this is through a layer of HSC.   Maybe Delco used a
> conductive HSC, but the factory stuff is the same white looking
> stuff I've always seen.
> 
> Negative diode failures are the most common cause of death for
> these alt's.  There is a new aftermarket design out, summit sells it,
> called the "iceberg"  It has fins on the rear case where the diodes
> mount.  I think my extra screw or conductive HSC , if I could find
> that, is the way to go.   105A is a lot of current to push through a
> resistive connection.
> 

I've seen many, many more mechanical failures in these than
electrical.  Mainly, the front bearing.  Maybe the area you're in has
to do with the type of failures you see.  
Shannen

> >
> >   Also , how is the negative diode in your alternator connected to ground? I
> > understand that you have no screws to ground it , except the 8-32 that you
> > have added. I am certain that Delco intended to provide a GOOD connection
> > between the negative diodes and ground --- in a negative ground alternator.
> >
> >   Or -- Have I misunderstood something here??
> >
> >        Jerry
> >
> 
> Randy Braun     rbraun at enter.net
> 30th Ann. T/A coming soon....
> 91  GTA   for sale
> 82 Firebird